PRIME Minister Tony Blair will give his support today to the official launch of Britain's first major offshore wind farm and the start of its delivery of electricity ashore.

The North Hoyle Offshore Windfarm, about five miles off the North Wales coast, bet- ween Prestatyn and Rhyl, is to be officially "switched on" at events staged jointly in North Wales and London by energy suppliers Npower and environmental group Greenpeace.

The event, which is a key step in the battle towards cutting the UK's greenhouse gas emissions, will be attended in London by Energy Minister Stephen Timms.

Tony Blair will make an address to be broadcast at both events, praising the alliance between Npower and Greenpeace.

Mr Blair will tell those gathered for the switch on, "Rolling out this first large- scale offshore wind venture is a highly significant step toward achieving Britain's renewables goal.

"We are on our way to a future that can be transformed by the use of clean forms of energy. I look forward to celebrating further successes with you along the way."

Spokesman for Friends of the Earth Cymru, Neil Crumpton, described off-shore wind as a "superb" and "potentially very significant technology".

"Off-shore wind can supply a large part of our energy needs. There are virtually no carbon dioxide and green house gas emissions, which are the main cause of global warming.

"Also there are no acid gas emissions which have done so much to damage the fragile ecology of Mid Wales and it's our own energy so we are not reliant on anybody else."

But Royal Society for the Protection of Birds Cymru's conservation officer, Mike Webb, warned that the populations of red-throated diver and common scoter in the area would have to be carefully monitored to ensure they do not decline following the switch-on.

"In the vicinity of Liverpool Bay these are two bird species with internationally important numbers," he said.

"The population there is an internationally important site - there is a large percentage of the world or international population, which in the case of the Common Scoter, would be wintering there.

"That's why the monitoring is so important and will continue to be so."

The project took eight months to complete and will offset the release of 160,000 tonnes of carbon dioxide into the atmosphere per year. The 30 turbines will supply power for up to 50,000 homes.

Andrew Duff, chief executive of Npower and RWE Innogy, which built North Hoyle, said it is a tangible symbol to people who want to protect the environment.

"All too often people think of the big issues like global warming and feel powerless to do anything about it.

"Through our clean electricity, we can help people across the country make a difference.

"Stephen Tindale, executive director of Greenpeace UK, welcomed North Hoyle's completion and urged more action to encourage the development of renewable technologies.

"This is the beginning of mainstream wind power development and the dawn of a new clean energy era for Britain. Global warming is the greatest threat facing the planet, but the power flowing ashore today demonstrates we have the solutions to tackle it.

"It's great news for all our futures."

The wind farm will have a capacity of 60 megawatts.

WITHIN 12 miles of British shores it is possible to generate three times our electricity needs through off-shore wind power, according to FoE Cymru.

To generate all of Britain's annual electricity, 45 gigawatts, we would require 29,000 off-shore turbines and 4,500 on-shore turbines.

Germany has approaching 15,000 on-shore wind-turbines, compared with just 1,000 on-shore in the UK.

Also the UK has little more than 32 off-shore wind farms, but consent is expected to be given for up to 18 others, and over the next few years the number of turbine schemes out at sea could reach 400.

Also, as the technology improves, companies get more experienced and investors' confidence grows, turbines can be placed further out to sea.